Salvatore Romano - Academia.edu (original) (raw)

Papers by Salvatore Romano

Research paper thumbnail of Teste de pressão negativa expiratória: um novo método simples para identificar pacientes com risco para apneia obstrutiva do sono

Jornal Brasileiro de Pneumologia, 2011

O objetivo deste artigo foi descrever um novo método para avaliar a limitação ao fluxo expiratóri... more O objetivo deste artigo foi descrever um novo método para avaliar a limitação ao fluxo expiratório durante a respiração espontânea, possibilitando a identificação do risco para apneia obstrutiva do sono através do teste de pressão negativa expiratória. A colapsabilidade da via aérea superior é avaliada pela medida da queda de fluxo e de volume expirado a 0,2 segundos imediatamente após a aplicação de pressão negativa expiratória de 10 cmH2O. O teste de pressão negativa expiratória é de fácil aplicação e poderia ser utilizado na avaliação da limitação ao fluxo expiratório causada por obstrução da via aérea superior em sujeitos portadores de apneia obstrutiva do sono.

Research paper thumbnail of Influence of interface and position on upper airway collapsibility assessed by negative expiratory pressure

Sleep & breathing = Schlaf & Atmung, Jan 7, 2017

Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway colla... more Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway collapsibility in patients with obstructive sleep apnea (OSA). Most studies evaluated NEP using a mouthpiece that may exclude the cephalic portion of the upper airway. We hypothesize that NEP determination is influenced by interface and position. We evaluated patients with suspected OSA using polysomnography, NEP (-5 cmH2O in sitting and supine position with mouthpiece and nasal mask). A subgroup also underwent computed tomography (CT) of the upper airway. We studied a total of 86 subjects (72 male, age 46 ± 12 yrs, body mass index 30.0 ± 4.4 kg/m(2), neck circumference 40.0 ± 3.5 cm, AHI 32.9 ± 26.4, range 0.5 to 122.5 events/hour). NEP was influenced by interface and position (p = 0.007), and upper airway was more collapsible with mouthpiece than with nasal mask in sitting position (p = 0.001). Position influenced NEP and was worse in supine only when evaluated by nasal mask. Expiratory res...

Research paper thumbnail of Immediate effect of CPAP titration on perceived health related quality of life: a prospective observational study

BMC Pulmonary Medicine, 2016

Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apn... more Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). This study examines changes in HRQoL aspects occurring immediately after CPAP titration. Furthermore, we analyzed variations in each gender and in patients undergoing home or laboratory-based CPAP titration pathways. Methods: Twohundredfive outpatients (151 M) (56.7 ± 10.3 years) were evaluated, before first visit and nocturnal diagnostic examination (T0), and the morning after CPAP titration (T1). Two self-reported HRQoL questionnaires were administered: Psychological General Well-Being Index (PGWBI), composed by six subscales, and 12-Item Short-Form Health Survey (SF-12), including Physical (PCS) and Mental Component Summaries (MCS). CPAP titration was performed using auto-adjusting CPAP units at patients' home or in the sleep laboratory. Results: PGWBI scores at T1 improved compared to T0 (p < 0.0001). A similar improvement was observed in SF-12 MCS (p = 0.0011), but not in SF-12 PCS. Changes were independent from anthropometric parameters, OSA severity and excessive daytime sleepiness. Gender comparisons showed better HRQoL in males at both times. At T0, patients who received home or laboratory CPAP titration pathways did not show any differences in PGWBI and SF-12 scores. At T1, PGWBI and SF-12 MCS improved in both home and laboratory groups. Conclusions: This study gives evidence that first time CPAP application for titration can lead to a general increase in perceived well-being. Gender comparisons showed better perceived HRQoL with more subscales improvements in males after CPAP titration. The improvement was similar with both home and laboratory CPAP titration pathways.

Research paper thumbnail of Gel pillow designed specifically for obstructive sleep apnea treatment with continuous positive airway pressure

Jornal Brasileiro de Pneumologia, 2016

Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate... more Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. Methods: Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with an appropriate CPAP mask and were instructed to use CPAP for 15 nights. They were instructed to sleep with their own pillow (the control pillow) from nights 1 to 5 and with either a foam pillow or a gel pillow, both of which had side cutouts, for 5 consecutive nights each, in random order. After night 15, auto-CPAP machine data were downloaded and patients rated their satisfaction with each pillow on a visual analog scale. Results: Twenty-two patients completed the protocol. The pressures administered, residual apnea-hypopnea index, air leaks, and mean duration of CPAP use did not differ among th...

Research paper thumbnail of A Systematic Review of Negative Expiratory Pressure Test as Screening to Obstructive Sleep Apnoea

Sleep Science, 2015

Insônia (14 e 4) e DBASÀ 10 (59 e 12). Em relação ao Diário de Sono também houve melhora semana a... more Insônia (14 e 4) e DBASÀ 10 (59 e 12). Em relação ao Diário de Sono também houve melhora semana a semana, partindo de uma Eficiência de Sono de 36% no início da terapia que chegou a 94,1% ao final do tratamento. Conclusão É extremamente importante considerar a utilização de TCC para pacientes portadores de insônia crônica, inclusive em grandes hospitais.

Research paper thumbnail of Usefulness of a medical support assistance on CPAP compliance

European Respiratory Journal, Sep 1, 2013

Research paper thumbnail of Heart rate variability during sleep at high altitude: effect of periodic breathing

Sleep and Breathing, 2015

Background: Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a... more Background: Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. Purpose: The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization i.e. two different levels of hypoxemia. Methods: Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the 1st (BC1) and the 10th (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. Results: A mean overnight RR reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due by RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. Conclusions: The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Research paper thumbnail of Effect of obstructive sleep apnea diagnosis on health related quality of life

Health and Quality of Life Outcomes, 2015

Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apn... more Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). To our knowledge, no study has analyzed the effect of OSA diagnosis communication on HRQoL. We evaluated self-perceived HRQoL in patients afferent to our sleep center, in order to examine the effect of the diagnosis disclosure on their HRQoL. Methods: Two hundred ninety-seven consecutive outpatients (227 M) (mean age 54.1 ± 11.6 yrs, range 23-80 yrs) were evaluated, before first clinical visit and nocturnal diagnostic examination (Time A), and after diagnosis disclosure (Time B), with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), consisting of anxiety, depressed mood, positive well-being, self-control, general health, vitality subscales, and 12-Item Short-Form Health Survey (SF-12), comprising Physical (PCS) and Mental Component Summaries (MCS). Results: Comparison of mean HRQoL scores at Time A with reference values, showed worse scores. Mean PGWBI Total and subscales scores improved at Time B. Similar improvement was observed for SF-12 MCS (p = 0.0148), but nor for SF-12 PCS. At Time B, Anxiety, Depression and Well-being PGWBI subscales became similar to reference values, while the scores in the other PGWBI subscales and SF-12 remained worse. Comparison between males and females showed higher HRQoL values for males at both times. Score changes were independent from age, gender, BMI, AHI, TSat 90 and excessive daytime sleepiness. Conclusions: Diagnosis communication improves patients' HRQoL, regardless of the severity. Changes in HRQoL after diagnosis disclosure may be due to patients' motivation for medical check and diagnostic expectations.

Research paper thumbnail of Usefulness of reinforcing interventions on continuous positive airway pressure compliance

BMC Pulmonary Medicine, 2014

Background: Obstructive sleep apnea (OSA) is a high prevalence sleep disorder characterized by up... more Background: Obstructive sleep apnea (OSA) is a high prevalence sleep disorder characterized by upper airway obstruction during sleep, nocturnal intermittent hypoxemia, poor sleep quality, risk for cardiovascular and metabolic diseases. The adherence to CPAP is the key for an effective management of these patients. The aim of the study was to assess the adherence to CPAP therapy with and without early reinforcing interventions, consisting of motivational reinforcement and technical support in the first month of therapy. Methods: Forty patients with OSA undergoing counseling and a one year follow-up on a quarterly basis were included in the study. Twenty subjects (intervention group) underwent reinforcing interventions with telephone interviews in the first month of therapy, and twenty (control group) remained without reinforcing interventions. The two populations were homogeneous for age, severity of illness and BMI. Results: During the first month, intervention group patients showed a higher number of nights with a device use ≥4 hours. Average treatment adherence in the first month (days of therapy with at least 4 hours per night on the total number of days from device delivery) was 77.5% in the intervention group and 55.7% in the control group (p = 0.022). At one year the differences between the two groups were not significant. Conclusions: Our findings suggest that it is important that adequate time and effort is spent to ensure patient comfort at the time of CPAP therapy start to optimize acceptance and adherence to treatment, and suggest that it is necessary to maintain reinforcing interventions over time.

Research paper thumbnail of Respiratory sinus arrhythmia during obstructive sleep apnoeas in humans

Journal of Sleep Research, 1995

Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during ... more Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during the respiratory cycle. Since the time-course of RSA during obstructive sleep apnoea (OSA) is not known, an analysis was made of ECG in samples of consecutive OSA recorded in 5 patients during NREM sleep while breathing room air (OSA-AIR, mean lowest SaO2 83.0 +/- 6.5%) or supplemental oxygen (OSA +/- O2, mean lowest SaO2 91.7 +/- 2.2%), respectively. For each breath, HR at the transition from expiration to inspiration (HRei), and HR at maximal inspiration (HRie) were calculated, and the inspiratory increase in HR estimated as the ratio: HRie/subsequent HRie. Similarly, the expiratory decrease in HR was estimated as: HRie/subsequent HRei. RSA was identified by an inspiratory increase in HR (HRei/HRie &lt; 1), and an expiratory decrease in HR (HRie/HRei &gt; 1). OSA-AIR and OSA + O2 did not differ for duration or oesophageal pressure nadir. During OSA-AIR, the inspiratory increase in HR became progressively more marked from the first occluded to the first open breath, whereas during OSA + O2 it remained stable throughout the apnoeic cycle. The expiratory decrease in HR remained constant during the apnoeic phase, but was blunted in the first open breaths irrespective of O2 administration. In summary, hypoxia appeared to affect inspiratory, but not expiratory HR. Instead, the expiratory slowing of HR transiently disappeared in the immediate post-apnoeic phase, suggesting a possible effect of arousal or pulmonary inflation. These data suggest that the parasympathetic system may contribute to cardiovascular regulation during OSA.

Research paper thumbnail of Rate during Sleep in Severe Obstructive Sleep Apnea Syndrome Continuous Positive Airway Pressure Treatment Improves Baroreflex Control of Heart

Blood pressure and heart rate during periodic breathing while asleep at high altitude. J Appl Phy... more Blood pressure and heart rate during periodic breathing while asleep at high altitude. J Appl Physiol 89: 947-955, 2000.-The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulness progressively increased in normal subjects staying 4 wk at 5,050 m (

Research paper thumbnail of Periodic Breathing, Arterial Oxyhemoglobin Saturation, and Heart Rate during Sleep at High Altitude

High Altitude Medicine & Biology, 2012

The aim of this study was to investigate the effects of acclimatization to high altitude on perio... more The aim of this study was to investigate the effects of acclimatization to high altitude on periodic breathing (PB), arterial oxygen saturation (Sao(2)), and heart rate (HR). Nine male elite climbers, age 24-52 years underwent overnight cardiorespiratory monitoring at sea level and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) nights. PB was commonplace in all subjects at high altitude. PB cycle duration increased (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001) from BC1 (21.7±1.9 s) to BC2 (26.7±2.1 s). Mean Sao(2) from BC1 to BC2, significantly increased during wakefulness (77.4±3.4% vs. 82.5±2.8%; p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and during sleep regular breathing (73.3±3.8% vs. 77.8±2.9%; p=0.022). During PB, mean higher Sao(2) was 75.3±3.6% at BC1 and 82.4±2.9% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001); mean lower Sao(2) was 68.2±4.0% at BC1 and 74.5±4.3% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). During PB, mean higher HR was 72.4±8.8 b/min at BC1 and 63.3±6.0 b/min at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0002); mean lower HR were 53.6±7.5% at BC1 and 43.6±7.3% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The mean Sao(2) during PB compared with Sao(2) at night without PB was unchanged. Acclimatization to high altitude resulted in an overall increase in Sao(2) along with an increase in the PB cycle duration and a decrease in HR.

Research paper thumbnail of Quality of life in patients at first time visit for sleep disorders of breathing at a sleep centre

Health and Quality of Life Outcomes, 2013

Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstr... more Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstructive sleep apnea (OSA) patients have several typical symptoms including habitual snoring, excessive daytime sleepiness, fatigue, lack of concentration, memory impairment, and at times psychological disturbances. We evaluated different aspects in the health related quality of life (HRQoL) in subjects referred to our sleep laboratory for their first examination for suspicion of OSA. Methods: One hundred ninety-eight consecutive outpatients (152 M) (mean age 52.7 ± 12.8 years, range 18-82 years; mean BMI 31.0 ± 6.5 kg/m 2 , range 17.3-57.8 kg/m 2) were evaluated with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), that asses anxiety, depressed mood, positive well-being, self-control, general health, vitality, and 12-Item Short-Form Health Survey (SF-12), consisting assesses of Physical and Mental Component Summaries (PCS and MCS). Epworth Sleepiness Scale (ESS) was used to assess daytime sleepiness before nocturnal diagnostic examination. Results: Subjects showed variable HRQoL scores. HRQoL was worse in women than men and it decreased with age. No relation was found with AHI severity (range 0-129 n/h). BMI and TSat 90 (range 0-87.9%) affected physical health perception (SF-12 PCS). Furthermore TSat 90 influenced PGWBI Vitality subscale. Subjects with ESS > 10 showed a worse HRQoL profile (p < 0.001) in SF-12 and in PGWBI. Multiple regression analysis showed that age, BMI and ESS were significant predictors of SF-12 PCS (p < 0.001; r 2 = 0.23). Conclusions: A worse HRQoL perception among subjects referred for OSA suspicion was not related to disease severity. BMI and hypoxemia influenced only some HRQoL dimensions, while excessive daytime sleepiness worsens all HRQoL components considered.

Research paper thumbnail of Automatic Titration and Calculation by Predictive Equations for the Determination of Therapeutic Continuous Positive Airway Pressure for Obstructive Sleep Apnea

Chest, 2008

complicated by obstructive sleep apnea (OSA). However, the effect on the prognosis of such patien... more complicated by obstructive sleep apnea (OSA). However, the effect on the prognosis of such patients remains unknown. Aims.-To determine whether CPAP therapy and compliance affects the prognosis of HF patients with OSA. Methods.-We classified 88 patients with HF and moderate-to-severe OSA into a CPAP-treated group (n ¼ 65) and an untreated group (n ¼ 23), and then those treated with CPAP were further subclassified according to CPAP therapy compliance. The frequency of death and hospitalization was analyzed using multivariate analysis. Results.-During a mean (± SD) period of 25.3 ± 15.3 months, 44.3% of the patients died or were hospitalized. Multivariate analysis showed that the risk for death and hospitalization was increased in the untreated group (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.07 to 3.68; p ¼ 0.030) and in less compliant CPAP-treated patients (HR, 4.02; 95% CI, 1.33 to 12.2; p ¼ 0.014). Conclusion.-Therapy with CPAP significantly reduced the risk of death and hospitalization among patients with HF and OSA. However, reduced compliance with CPAP therapy was significantly associated with an increased risk of death and hospitalization. : This was an interesting hypothesis-generating analysis. It showed a relationship between the use of continuous positive airway pressure (CPAP) in patients with congestive heart failure (CHF) and a composite of death and hospitalizations, as well as a relationship between compliance with CPAP treatment and noncompliance. Unfortunately, because of the nature of a prospective observational study and the small number of events, no definitive answer has been reached. A larger study is needed to confirm the findings. Further research into the mechanisms to explain this are needed, but they may be related to hypoxia-induced inflammation and sympathetic activity. If the treatment group had 1 more death or if the nontreated group had 1 more survival, a mortality benefit could not have been reached.

Research paper thumbnail of Sleep Structure Correlates of Continuous Positive Airway Pressure Variations During Application of an Autotitrating Continuous Positive Airway Pressure Machine in Patients With Obstructive Sleep Apnea Syndrome

Chest, 2002

Study objectives: To evaluate the relationship between sleep structure and continuous positive ai... more Study objectives: To evaluate the relationship between sleep structure and continuous positive airway pressure (CPAP) delivered by an automatic CPAP (auto-CPAP) machine in patients with obstructive sleep apnea syndrome (OSAS). Design: Nocturnal polysomnography was performed during CPAP administration by an auto-CPAP machine (Autoset Clinical 1; ResMed; Sydney, Australia). Setting: Sleep-disorders center in a research institute. Patients: Fifteen subjects with newly diagnosed OSAS deserving home CPAP treatment. Measurements and results: During the night, in most cases, the lowest CPAP level was recorded during a prolonged nonrapid eye movement (NREM) sleep period uninterrupted by arousals, whereas the highest level during wake-sleep transitions or NREM sleep fragmented by arousals. In four subjects, rapid eye movement sleep was always associated with increasing CPAP. Sleep efficiency was negatively correlated with CPAP variability, evaluated as the SD of the mean nocturnal CPAP level averaged epoch by epoch (r ‫؍‬ 0.63, p < 0.02). Eighty-eight percent of rapid CPAP augmentations (increases by at least 2 cm H 2 O in < 2 min) were observed during sleep-wake transitions or after arousals/awakenings (Ar/Aw); 63% of such Ar/Aw were not preceded by any detectable respiratory abnormality. Conclusions: CPAP levels and variations during auto-CPAP application may be mainly related to sleep continuity and efficiency. The recording of a highly variable pressure during auto-CPAP administration in an unattended environment must raise the question whether the patient's sleep quality was acceptable. A poor sleep quality during an autotitration night could lead to an undesirable overestimation of the CPAP level needed for use with fixed-level CPAP machines.

Research paper thumbnail of General Characteristics and Risk Factors of Cardiovascular Disease among Interstate Bus Drivers

The Scientific World Journal, 2012

Workers in the transportation industry are at greater risk of an incorrect diet and sedentary beh... more Workers in the transportation industry are at greater risk of an incorrect diet and sedentary behavior. The aim of our study was to characterize a population of professional bus drivers with regard to clinical and demographic variables, lipid profile, and the presence of cardiovascular risk factors. Data from 659 interstate bus drivers collected retrospectively, including anthropometric characteristics, systolic and diastolic blood pressure, lipid profile, fasting blood glucose, meatoscopy, and audiometry. All participants were male, with a mean age of41.7±6.9years, weight of81.4±3.3 kg, and BMI27.2±3.3 Kg/m2; the mean abdominal and neck circumferences were94.4±8.6 cm and38.9±2.2 cm; 38.2% of the sample was considered hypertensive; mean HDL cholesterol was47.9±9.5 mg/dL, mean triglyceride level was146.3±87.9 mg/dL, and fasting glucose was above 100 mg/dL in 249 subjects (39.1%). Drivers exhibited reduced audiometric hearing at 4–8 kHz, being all sensorineural hearing loss. The clini...

Research paper thumbnail of A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

Clinics, 2011

Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. T... more Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V 0.2 , V 0.5 , and V 1.0 , respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p,0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V 0.2 (%) predictive parameters for the detection of sleep apnea were sensitivity (81.1%), specificity (93.1%), PPV (98.1%), and NPV (52.9%). Sensitivity and NPV were 96.9% and 93.2%, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100% for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 (%) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.

Research paper thumbnail of Upper airway collapsibility evaluated by a negative expiratory pressure test in severe obstructive sleep apnea

Research paper thumbnail of The New Tool to Screening Obstructive Sleep Apnoea: Negative Expiratory Pressure Test

Sleep Science, 2015

Recent studies have shown that the fluid shift from the leg to the neck when the subject assumes ... more Recent studies have shown that the fluid shift from the leg to the neck when the subject assumes the supine position contributes to upper airway collapsibility during sleep. However, the dependence of different postures in fluid has not been completely elucidated. We hypothesized that posture (supine vs sitting position) will have opposite effects on fluid shift displacement. Methods This was a cross over study in which 18 healthy male subjects remained still for 60 minutes at the supine or seated position. The experiments in the 2 postures were done in different days and the sequence was randomized. Segmental bioimpedance (InBody S10, Biospace), cervical, abdomen and calves circumferences and were measured at time 0 and 60 minutes. Results The subjects were characterized by: age and body mass index 24.0972.57 kg/m 2. Baseline parameters were similar in supine position at the beginning of the study in both positions and were: cervical circumference 38.4671.45 cm, right calf circumference 38.2072.32 left calf circumference 38.2772.10. Changes in leg segmental water in the supine position vs sitting position were significantly different (change: left leg: decrease of 127 ml70.164 in supine vs increase of 144 ml70.300 in seated position (p¼ 0.03). Right leg: decrease of 159 ml70.154 in supine vs increase of 52 ml70.110 in seated position (p¼0.03). Right calf circumference raised 0.60 cm70.33 in seated position while decreased 0.57 cm70.51. Left calf raised 143 ml70.269 vs decreased 127 ml70.269 (p¼0.03). Cervical circumference raised 0.54 cm70.57 and reduced 0.60 cm760 in the supine position (po0.0001). Conclusion Human body is subjected to significant posture dependent fluid shift. One hour at the sitting position is sufficient for a significant liquid accumulation in the legs with a decrease in neck circumference.

Research paper thumbnail of Upper Airway Collapsibility Assessed by Negative Expiratory Pressure While Awake is Associated With Upper Airway Anatomy

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Oct 19, 2016

There is a growing interest to develop a simple method to characterize the mechanisms leading to ... more There is a growing interest to develop a simple method to characterize the mechanisms leading to upper airway collapse in order to guide treatment options in patients with obstructive sleep apnea (OSA). Critical closing pressure (Pcrit) during sleep is able to predict the anatomical component of OSA. However, Pcrit is a laborious method that is only used for research purposes. The application of negative expiratory pressure (NEP) is a simple method to assess upper airway collapsibility that can be easily performed during wakefulness. We hypothesized that NEP will be, similarly to Pcrit, associated with upper airway anatomy assessed by computed tomography (CT) scan. Patients under investigation for OSA underwent polysomnography, CT of the upper airway, NEP while awake, and Pcrit during sleep. NEP was performed with -5cmH2O in supine position using a nasal mask. Pcrit was measured during sleep induced by low doses of midazolam. Twenty-eight male subjects were studied (age 45 ± 13 y, b...

Research paper thumbnail of Teste de pressão negativa expiratória: um novo método simples para identificar pacientes com risco para apneia obstrutiva do sono

Jornal Brasileiro de Pneumologia, 2011

O objetivo deste artigo foi descrever um novo método para avaliar a limitação ao fluxo expiratóri... more O objetivo deste artigo foi descrever um novo método para avaliar a limitação ao fluxo expiratório durante a respiração espontânea, possibilitando a identificação do risco para apneia obstrutiva do sono através do teste de pressão negativa expiratória. A colapsabilidade da via aérea superior é avaliada pela medida da queda de fluxo e de volume expirado a 0,2 segundos imediatamente após a aplicação de pressão negativa expiratória de 10 cmH2O. O teste de pressão negativa expiratória é de fácil aplicação e poderia ser utilizado na avaliação da limitação ao fluxo expiratório causada por obstrução da via aérea superior em sujeitos portadores de apneia obstrutiva do sono.

Research paper thumbnail of Influence of interface and position on upper airway collapsibility assessed by negative expiratory pressure

Sleep & breathing = Schlaf & Atmung, Jan 7, 2017

Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway colla... more Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway collapsibility in patients with obstructive sleep apnea (OSA). Most studies evaluated NEP using a mouthpiece that may exclude the cephalic portion of the upper airway. We hypothesize that NEP determination is influenced by interface and position. We evaluated patients with suspected OSA using polysomnography, NEP (-5 cmH2O in sitting and supine position with mouthpiece and nasal mask). A subgroup also underwent computed tomography (CT) of the upper airway. We studied a total of 86 subjects (72 male, age 46 ± 12 yrs, body mass index 30.0 ± 4.4 kg/m(2), neck circumference 40.0 ± 3.5 cm, AHI 32.9 ± 26.4, range 0.5 to 122.5 events/hour). NEP was influenced by interface and position (p = 0.007), and upper airway was more collapsible with mouthpiece than with nasal mask in sitting position (p = 0.001). Position influenced NEP and was worse in supine only when evaluated by nasal mask. Expiratory res...

Research paper thumbnail of Immediate effect of CPAP titration on perceived health related quality of life: a prospective observational study

BMC Pulmonary Medicine, 2016

Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apn... more Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). This study examines changes in HRQoL aspects occurring immediately after CPAP titration. Furthermore, we analyzed variations in each gender and in patients undergoing home or laboratory-based CPAP titration pathways. Methods: Twohundredfive outpatients (151 M) (56.7 ± 10.3 years) were evaluated, before first visit and nocturnal diagnostic examination (T0), and the morning after CPAP titration (T1). Two self-reported HRQoL questionnaires were administered: Psychological General Well-Being Index (PGWBI), composed by six subscales, and 12-Item Short-Form Health Survey (SF-12), including Physical (PCS) and Mental Component Summaries (MCS). CPAP titration was performed using auto-adjusting CPAP units at patients' home or in the sleep laboratory. Results: PGWBI scores at T1 improved compared to T0 (p < 0.0001). A similar improvement was observed in SF-12 MCS (p = 0.0011), but not in SF-12 PCS. Changes were independent from anthropometric parameters, OSA severity and excessive daytime sleepiness. Gender comparisons showed better HRQoL in males at both times. At T0, patients who received home or laboratory CPAP titration pathways did not show any differences in PGWBI and SF-12 scores. At T1, PGWBI and SF-12 MCS improved in both home and laboratory groups. Conclusions: This study gives evidence that first time CPAP application for titration can lead to a general increase in perceived well-being. Gender comparisons showed better perceived HRQoL with more subscales improvements in males after CPAP titration. The improvement was similar with both home and laboratory CPAP titration pathways.

Research paper thumbnail of Gel pillow designed specifically for obstructive sleep apnea treatment with continuous positive airway pressure

Jornal Brasileiro de Pneumologia, 2016

Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate... more Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. Methods: Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with an appropriate CPAP mask and were instructed to use CPAP for 15 nights. They were instructed to sleep with their own pillow (the control pillow) from nights 1 to 5 and with either a foam pillow or a gel pillow, both of which had side cutouts, for 5 consecutive nights each, in random order. After night 15, auto-CPAP machine data were downloaded and patients rated their satisfaction with each pillow on a visual analog scale. Results: Twenty-two patients completed the protocol. The pressures administered, residual apnea-hypopnea index, air leaks, and mean duration of CPAP use did not differ among th...

Research paper thumbnail of A Systematic Review of Negative Expiratory Pressure Test as Screening to Obstructive Sleep Apnoea

Sleep Science, 2015

Insônia (14 e 4) e DBASÀ 10 (59 e 12). Em relação ao Diário de Sono também houve melhora semana a... more Insônia (14 e 4) e DBASÀ 10 (59 e 12). Em relação ao Diário de Sono também houve melhora semana a semana, partindo de uma Eficiência de Sono de 36% no início da terapia que chegou a 94,1% ao final do tratamento. Conclusão É extremamente importante considerar a utilização de TCC para pacientes portadores de insônia crônica, inclusive em grandes hospitais.

Research paper thumbnail of Usefulness of a medical support assistance on CPAP compliance

European Respiratory Journal, Sep 1, 2013

Research paper thumbnail of Heart rate variability during sleep at high altitude: effect of periodic breathing

Sleep and Breathing, 2015

Background: Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a... more Background: Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. Purpose: The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization i.e. two different levels of hypoxemia. Methods: Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the 1st (BC1) and the 10th (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. Results: A mean overnight RR reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due by RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. Conclusions: The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Research paper thumbnail of Effect of obstructive sleep apnea diagnosis on health related quality of life

Health and Quality of Life Outcomes, 2015

Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apn... more Background: Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). To our knowledge, no study has analyzed the effect of OSA diagnosis communication on HRQoL. We evaluated self-perceived HRQoL in patients afferent to our sleep center, in order to examine the effect of the diagnosis disclosure on their HRQoL. Methods: Two hundred ninety-seven consecutive outpatients (227 M) (mean age 54.1 ± 11.6 yrs, range 23-80 yrs) were evaluated, before first clinical visit and nocturnal diagnostic examination (Time A), and after diagnosis disclosure (Time B), with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), consisting of anxiety, depressed mood, positive well-being, self-control, general health, vitality subscales, and 12-Item Short-Form Health Survey (SF-12), comprising Physical (PCS) and Mental Component Summaries (MCS). Results: Comparison of mean HRQoL scores at Time A with reference values, showed worse scores. Mean PGWBI Total and subscales scores improved at Time B. Similar improvement was observed for SF-12 MCS (p = 0.0148), but nor for SF-12 PCS. At Time B, Anxiety, Depression and Well-being PGWBI subscales became similar to reference values, while the scores in the other PGWBI subscales and SF-12 remained worse. Comparison between males and females showed higher HRQoL values for males at both times. Score changes were independent from age, gender, BMI, AHI, TSat 90 and excessive daytime sleepiness. Conclusions: Diagnosis communication improves patients' HRQoL, regardless of the severity. Changes in HRQoL after diagnosis disclosure may be due to patients' motivation for medical check and diagnostic expectations.

Research paper thumbnail of Usefulness of reinforcing interventions on continuous positive airway pressure compliance

BMC Pulmonary Medicine, 2014

Background: Obstructive sleep apnea (OSA) is a high prevalence sleep disorder characterized by up... more Background: Obstructive sleep apnea (OSA) is a high prevalence sleep disorder characterized by upper airway obstruction during sleep, nocturnal intermittent hypoxemia, poor sleep quality, risk for cardiovascular and metabolic diseases. The adherence to CPAP is the key for an effective management of these patients. The aim of the study was to assess the adherence to CPAP therapy with and without early reinforcing interventions, consisting of motivational reinforcement and technical support in the first month of therapy. Methods: Forty patients with OSA undergoing counseling and a one year follow-up on a quarterly basis were included in the study. Twenty subjects (intervention group) underwent reinforcing interventions with telephone interviews in the first month of therapy, and twenty (control group) remained without reinforcing interventions. The two populations were homogeneous for age, severity of illness and BMI. Results: During the first month, intervention group patients showed a higher number of nights with a device use ≥4 hours. Average treatment adherence in the first month (days of therapy with at least 4 hours per night on the total number of days from device delivery) was 77.5% in the intervention group and 55.7% in the control group (p = 0.022). At one year the differences between the two groups were not significant. Conclusions: Our findings suggest that it is important that adequate time and effort is spent to ensure patient comfort at the time of CPAP therapy start to optimize acceptance and adherence to treatment, and suggest that it is necessary to maintain reinforcing interventions over time.

Research paper thumbnail of Respiratory sinus arrhythmia during obstructive sleep apnoeas in humans

Journal of Sleep Research, 1995

Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during ... more Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during the respiratory cycle. Since the time-course of RSA during obstructive sleep apnoea (OSA) is not known, an analysis was made of ECG in samples of consecutive OSA recorded in 5 patients during NREM sleep while breathing room air (OSA-AIR, mean lowest SaO2 83.0 +/- 6.5%) or supplemental oxygen (OSA +/- O2, mean lowest SaO2 91.7 +/- 2.2%), respectively. For each breath, HR at the transition from expiration to inspiration (HRei), and HR at maximal inspiration (HRie) were calculated, and the inspiratory increase in HR estimated as the ratio: HRie/subsequent HRie. Similarly, the expiratory decrease in HR was estimated as: HRie/subsequent HRei. RSA was identified by an inspiratory increase in HR (HRei/HRie &lt; 1), and an expiratory decrease in HR (HRie/HRei &gt; 1). OSA-AIR and OSA + O2 did not differ for duration or oesophageal pressure nadir. During OSA-AIR, the inspiratory increase in HR became progressively more marked from the first occluded to the first open breath, whereas during OSA + O2 it remained stable throughout the apnoeic cycle. The expiratory decrease in HR remained constant during the apnoeic phase, but was blunted in the first open breaths irrespective of O2 administration. In summary, hypoxia appeared to affect inspiratory, but not expiratory HR. Instead, the expiratory slowing of HR transiently disappeared in the immediate post-apnoeic phase, suggesting a possible effect of arousal or pulmonary inflation. These data suggest that the parasympathetic system may contribute to cardiovascular regulation during OSA.

Research paper thumbnail of Rate during Sleep in Severe Obstructive Sleep Apnea Syndrome Continuous Positive Airway Pressure Treatment Improves Baroreflex Control of Heart

Blood pressure and heart rate during periodic breathing while asleep at high altitude. J Appl Phy... more Blood pressure and heart rate during periodic breathing while asleep at high altitude. J Appl Physiol 89: 947-955, 2000.-The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulness progressively increased in normal subjects staying 4 wk at 5,050 m (

Research paper thumbnail of Periodic Breathing, Arterial Oxyhemoglobin Saturation, and Heart Rate during Sleep at High Altitude

High Altitude Medicine & Biology, 2012

The aim of this study was to investigate the effects of acclimatization to high altitude on perio... more The aim of this study was to investigate the effects of acclimatization to high altitude on periodic breathing (PB), arterial oxygen saturation (Sao(2)), and heart rate (HR). Nine male elite climbers, age 24-52 years underwent overnight cardiorespiratory monitoring at sea level and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) nights. PB was commonplace in all subjects at high altitude. PB cycle duration increased (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001) from BC1 (21.7±1.9 s) to BC2 (26.7±2.1 s). Mean Sao(2) from BC1 to BC2, significantly increased during wakefulness (77.4±3.4% vs. 82.5±2.8%; p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and during sleep regular breathing (73.3±3.8% vs. 77.8±2.9%; p=0.022). During PB, mean higher Sao(2) was 75.3±3.6% at BC1 and 82.4±2.9% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001); mean lower Sao(2) was 68.2±4.0% at BC1 and 74.5±4.3% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). During PB, mean higher HR was 72.4±8.8 b/min at BC1 and 63.3±6.0 b/min at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0002); mean lower HR were 53.6±7.5% at BC1 and 43.6±7.3% at BC2 (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). The mean Sao(2) during PB compared with Sao(2) at night without PB was unchanged. Acclimatization to high altitude resulted in an overall increase in Sao(2) along with an increase in the PB cycle duration and a decrease in HR.

Research paper thumbnail of Quality of life in patients at first time visit for sleep disorders of breathing at a sleep centre

Health and Quality of Life Outcomes, 2013

Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstr... more Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstructive sleep apnea (OSA) patients have several typical symptoms including habitual snoring, excessive daytime sleepiness, fatigue, lack of concentration, memory impairment, and at times psychological disturbances. We evaluated different aspects in the health related quality of life (HRQoL) in subjects referred to our sleep laboratory for their first examination for suspicion of OSA. Methods: One hundred ninety-eight consecutive outpatients (152 M) (mean age 52.7 ± 12.8 years, range 18-82 years; mean BMI 31.0 ± 6.5 kg/m 2 , range 17.3-57.8 kg/m 2) were evaluated with two self-reported questionnaires for HRQoL assessment: Psychological General Well-Being Index (PGWBI), that asses anxiety, depressed mood, positive well-being, self-control, general health, vitality, and 12-Item Short-Form Health Survey (SF-12), consisting assesses of Physical and Mental Component Summaries (PCS and MCS). Epworth Sleepiness Scale (ESS) was used to assess daytime sleepiness before nocturnal diagnostic examination. Results: Subjects showed variable HRQoL scores. HRQoL was worse in women than men and it decreased with age. No relation was found with AHI severity (range 0-129 n/h). BMI and TSat 90 (range 0-87.9%) affected physical health perception (SF-12 PCS). Furthermore TSat 90 influenced PGWBI Vitality subscale. Subjects with ESS > 10 showed a worse HRQoL profile (p < 0.001) in SF-12 and in PGWBI. Multiple regression analysis showed that age, BMI and ESS were significant predictors of SF-12 PCS (p < 0.001; r 2 = 0.23). Conclusions: A worse HRQoL perception among subjects referred for OSA suspicion was not related to disease severity. BMI and hypoxemia influenced only some HRQoL dimensions, while excessive daytime sleepiness worsens all HRQoL components considered.

Research paper thumbnail of Automatic Titration and Calculation by Predictive Equations for the Determination of Therapeutic Continuous Positive Airway Pressure for Obstructive Sleep Apnea

Chest, 2008

complicated by obstructive sleep apnea (OSA). However, the effect on the prognosis of such patien... more complicated by obstructive sleep apnea (OSA). However, the effect on the prognosis of such patients remains unknown. Aims.-To determine whether CPAP therapy and compliance affects the prognosis of HF patients with OSA. Methods.-We classified 88 patients with HF and moderate-to-severe OSA into a CPAP-treated group (n ¼ 65) and an untreated group (n ¼ 23), and then those treated with CPAP were further subclassified according to CPAP therapy compliance. The frequency of death and hospitalization was analyzed using multivariate analysis. Results.-During a mean (± SD) period of 25.3 ± 15.3 months, 44.3% of the patients died or were hospitalized. Multivariate analysis showed that the risk for death and hospitalization was increased in the untreated group (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.07 to 3.68; p ¼ 0.030) and in less compliant CPAP-treated patients (HR, 4.02; 95% CI, 1.33 to 12.2; p ¼ 0.014). Conclusion.-Therapy with CPAP significantly reduced the risk of death and hospitalization among patients with HF and OSA. However, reduced compliance with CPAP therapy was significantly associated with an increased risk of death and hospitalization. : This was an interesting hypothesis-generating analysis. It showed a relationship between the use of continuous positive airway pressure (CPAP) in patients with congestive heart failure (CHF) and a composite of death and hospitalizations, as well as a relationship between compliance with CPAP treatment and noncompliance. Unfortunately, because of the nature of a prospective observational study and the small number of events, no definitive answer has been reached. A larger study is needed to confirm the findings. Further research into the mechanisms to explain this are needed, but they may be related to hypoxia-induced inflammation and sympathetic activity. If the treatment group had 1 more death or if the nontreated group had 1 more survival, a mortality benefit could not have been reached.

Research paper thumbnail of Sleep Structure Correlates of Continuous Positive Airway Pressure Variations During Application of an Autotitrating Continuous Positive Airway Pressure Machine in Patients With Obstructive Sleep Apnea Syndrome

Chest, 2002

Study objectives: To evaluate the relationship between sleep structure and continuous positive ai... more Study objectives: To evaluate the relationship between sleep structure and continuous positive airway pressure (CPAP) delivered by an automatic CPAP (auto-CPAP) machine in patients with obstructive sleep apnea syndrome (OSAS). Design: Nocturnal polysomnography was performed during CPAP administration by an auto-CPAP machine (Autoset Clinical 1; ResMed; Sydney, Australia). Setting: Sleep-disorders center in a research institute. Patients: Fifteen subjects with newly diagnosed OSAS deserving home CPAP treatment. Measurements and results: During the night, in most cases, the lowest CPAP level was recorded during a prolonged nonrapid eye movement (NREM) sleep period uninterrupted by arousals, whereas the highest level during wake-sleep transitions or NREM sleep fragmented by arousals. In four subjects, rapid eye movement sleep was always associated with increasing CPAP. Sleep efficiency was negatively correlated with CPAP variability, evaluated as the SD of the mean nocturnal CPAP level averaged epoch by epoch (r ‫؍‬ 0.63, p < 0.02). Eighty-eight percent of rapid CPAP augmentations (increases by at least 2 cm H 2 O in < 2 min) were observed during sleep-wake transitions or after arousals/awakenings (Ar/Aw); 63% of such Ar/Aw were not preceded by any detectable respiratory abnormality. Conclusions: CPAP levels and variations during auto-CPAP application may be mainly related to sleep continuity and efficiency. The recording of a highly variable pressure during auto-CPAP administration in an unattended environment must raise the question whether the patient's sleep quality was acceptable. A poor sleep quality during an autotitration night could lead to an undesirable overestimation of the CPAP level needed for use with fixed-level CPAP machines.

Research paper thumbnail of General Characteristics and Risk Factors of Cardiovascular Disease among Interstate Bus Drivers

The Scientific World Journal, 2012

Workers in the transportation industry are at greater risk of an incorrect diet and sedentary beh... more Workers in the transportation industry are at greater risk of an incorrect diet and sedentary behavior. The aim of our study was to characterize a population of professional bus drivers with regard to clinical and demographic variables, lipid profile, and the presence of cardiovascular risk factors. Data from 659 interstate bus drivers collected retrospectively, including anthropometric characteristics, systolic and diastolic blood pressure, lipid profile, fasting blood glucose, meatoscopy, and audiometry. All participants were male, with a mean age of41.7±6.9years, weight of81.4±3.3 kg, and BMI27.2±3.3 Kg/m2; the mean abdominal and neck circumferences were94.4±8.6 cm and38.9±2.2 cm; 38.2% of the sample was considered hypertensive; mean HDL cholesterol was47.9±9.5 mg/dL, mean triglyceride level was146.3±87.9 mg/dL, and fasting glucose was above 100 mg/dL in 249 subjects (39.1%). Drivers exhibited reduced audiometric hearing at 4–8 kHz, being all sensorineural hearing loss. The clini...

Research paper thumbnail of A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

Clinics, 2011

Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. T... more Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V 0.2 , V 0.5 , and V 1.0 , respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p,0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V 0.2 (%) predictive parameters for the detection of sleep apnea were sensitivity (81.1%), specificity (93.1%), PPV (98.1%), and NPV (52.9%). Sensitivity and NPV were 96.9% and 93.2%, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100% for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 (%) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.

Research paper thumbnail of Upper airway collapsibility evaluated by a negative expiratory pressure test in severe obstructive sleep apnea

Research paper thumbnail of The New Tool to Screening Obstructive Sleep Apnoea: Negative Expiratory Pressure Test

Sleep Science, 2015

Recent studies have shown that the fluid shift from the leg to the neck when the subject assumes ... more Recent studies have shown that the fluid shift from the leg to the neck when the subject assumes the supine position contributes to upper airway collapsibility during sleep. However, the dependence of different postures in fluid has not been completely elucidated. We hypothesized that posture (supine vs sitting position) will have opposite effects on fluid shift displacement. Methods This was a cross over study in which 18 healthy male subjects remained still for 60 minutes at the supine or seated position. The experiments in the 2 postures were done in different days and the sequence was randomized. Segmental bioimpedance (InBody S10, Biospace), cervical, abdomen and calves circumferences and were measured at time 0 and 60 minutes. Results The subjects were characterized by: age and body mass index 24.0972.57 kg/m 2. Baseline parameters were similar in supine position at the beginning of the study in both positions and were: cervical circumference 38.4671.45 cm, right calf circumference 38.2072.32 left calf circumference 38.2772.10. Changes in leg segmental water in the supine position vs sitting position were significantly different (change: left leg: decrease of 127 ml70.164 in supine vs increase of 144 ml70.300 in seated position (p¼ 0.03). Right leg: decrease of 159 ml70.154 in supine vs increase of 52 ml70.110 in seated position (p¼0.03). Right calf circumference raised 0.60 cm70.33 in seated position while decreased 0.57 cm70.51. Left calf raised 143 ml70.269 vs decreased 127 ml70.269 (p¼0.03). Cervical circumference raised 0.54 cm70.57 and reduced 0.60 cm760 in the supine position (po0.0001). Conclusion Human body is subjected to significant posture dependent fluid shift. One hour at the sitting position is sufficient for a significant liquid accumulation in the legs with a decrease in neck circumference.

Research paper thumbnail of Upper Airway Collapsibility Assessed by Negative Expiratory Pressure While Awake is Associated With Upper Airway Anatomy

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Oct 19, 2016

There is a growing interest to develop a simple method to characterize the mechanisms leading to ... more There is a growing interest to develop a simple method to characterize the mechanisms leading to upper airway collapse in order to guide treatment options in patients with obstructive sleep apnea (OSA). Critical closing pressure (Pcrit) during sleep is able to predict the anatomical component of OSA. However, Pcrit is a laborious method that is only used for research purposes. The application of negative expiratory pressure (NEP) is a simple method to assess upper airway collapsibility that can be easily performed during wakefulness. We hypothesized that NEP will be, similarly to Pcrit, associated with upper airway anatomy assessed by computed tomography (CT) scan. Patients under investigation for OSA underwent polysomnography, CT of the upper airway, NEP while awake, and Pcrit during sleep. NEP was performed with -5cmH2O in supine position using a nasal mask. Pcrit was measured during sleep induced by low doses of midazolam. Twenty-eight male subjects were studied (age 45 ± 13 y, b...